Gold for riding training. Travel time is a SIGNIFICANT time sink while using quests to level. You don't want to wait to get it. In fact, while questing, the second you ding 40/60/70/80 you'll want to hearth and train it IMMEDIATELY! 10304 gold is the base cost, which will be modified by reputation. Also, make sure you're in a guild with the 10% riding speed bonus unless you're a class that already gets a mount-speed buff.
No he's just not paying attention. The wanted quests are built into both the leveling guides and the "Zandalar Forever" achievement guide. They aren't in the rep guide because they are not repeatable and by the time you hit max level they should be done. You'll also notice the rep guide doesn't contain every single possible completable quest that rewards rep. It is designed to focus on repeatable objectives, world quests, large quest lines, and missions.
And... that was it. New NPCs offered a glimpse of some truly amazing armor and weapons, none of which are currently available to players (and datamining suggests it may be a while, if ever, before they are.) There were no new appearances for players to farm, no items or pets or toys or titles to obtain, no achievements to complete. There was no repeatable, truly farmable content.
If you’ve seen or heard people getting excited for World of Warcraft because it’s “getting back to its roots,” thanks to a renewed focus on the shared hatred between the game’s two major factions—Horde and Alliance—in its new Battle for Azeroth expansion, maybe you’re tempted to sign up and give the game a whirl. Or, if you haven’t played in years, perhaps you’re curious to see what’s changed.
Guild Banners. The Banner of Cooperation and Battle Standard of Coordination will increase the experience from kills. They both have a 10 minute cooldown, but when you use one, the other is only locked out for 2 minutes. I was very bad about using these, so it might be worth using a macro to drop them on your first attack against an enemy. Keep in mind you must have reputation with your guild before being able to buy these, so new character may have a bit of a wait before picking them up.
Tiragarde Sound and Stormsong Valley are both fairly similar zones, but Stormsong is a little longer, meaning that you might not even have to finish it to hit 120. Tiragarde also comes with a bit of a warning. There are plenty of side quests to do in the zone after you finish the story quests. Don’t do them. It’s not worth the time or the experience you’ll get.